Showing posts with label RedHat. Show all posts
Showing posts with label RedHat. Show all posts

Friday, September 12, 2014

When your VM gets stuck in suspended mode in Red Hat KVM...

I needed to re-do my network interfaces in KVM - make more bridged Ethernet connection for the VMs to use.  I totally forgot that I had a guest VM running as I began my reboot.  "Suspending SSB2" it says as I panic suddenly realizing what I had done.  It's ok - I've done this before I quickly remember.  It does a great job of automatically suspending and resuming UNLESS YOU JUST HAPPEN TO CHOSE THAT REBOOT TO SCREW UP THE NETWORK CONFIGURATION.

So, it reboots and networking is goofed.  I quickly see what I did, fix and reboot again.  This time it's ok but the SSB2 VM does not start.  I try to start it manually and get the message:

libvirtError: error creating macvtap type of interface: Device or resource busy

Whatever that means.  (It actually means I tried to un-suspend but couldn't talk to the iSCSI network so we're leaving it in limbo).  I google and google and find a lot of folks in the same boat.  They came up with some very iffy and convoluted solutions involving editing multiple XML files, etc.  I follow the threads to the bottom of each.  None of them seem quite right.

New to KVM, I try clonging the non-startable SSB2 and succeed.  It boots and works (requires a lot of network changes, but oh well).

Still not satisfied I see mention of "/var/lib/libvirt/qemu/save/rhel.save"  (it's ssb2.save in my case).  Again some very complicated procedures involving editing multiple XML files, etc. with no guaranteed results by the author.

Since I have a working clone, I figure "What the heck!  I'll just delete "/var/lib/libvirt/qemu/save/ssb2.save" and try starting.  It worked!  -Except for one snag - I already had an exact doppleganger running.  It locked up my virt-manager and the server hard.  After, rebooting all was well.

This worked for me.  On a TEST system.  Use at your own risk.